Variable ratio drive



Sept 6, 1949. w. LEHNERT VARIABLE RATIO DRIVE 3 Sheets-Sheet 1 FiledJan. 25, 1946 INVENTOR.

WAYNE LEHNERT Sept. 6, 1949. w. LEHNERT VARIABLE RATIO DRIVE 3Sheets-Sheet 2 Filed Jan. 25, 1946 ATTD RN EYE IN VEN TOR.

WAYNE LEHNERT a W. LEHNERT VARIABLE RATIO DRIVE Sept. 6, 1949.

5 Sheets-Sheet 3 Filed Jan. 25, 1946 w fi l INVENTOR.

WAYNE LEHNERT BY mjmw.

AITCI RN EYE Patented Sept. 6, i949 UNlTED STATES PATENT OFFICE.

VARIABLE RATIO DRIVE Wayne Lehnert, Peotone, 111.

Application January 325, 1946, Serial No. 643,263

The invention relates to a power transmission mechanism, and moreespecially to a friction gear transmission for motor vehicleconstruction.

The primary object of the invention is the provision of mechanismof thischaracter, wherein through vacuum within the motor a friction powertransmission is effected, and automatically a change of speed takesplace in accordancefwith the load variation, the transmission beingreversible at the will of the operator of the vehicle.

Another object of the invention is the provision of mechanism of thischaracter, wherein the transmission of motion from a driving source orpower unit to a driven source or unit will be had in a smooth, quiet andeffective manner, without any lost motion, and at the same time anoperator can manually control and vary the relation of speeds betweenthe driving and driven mediums, as well as a reversal of directionalmotion, without the use of gearing of the toothed type.

A further object of the invention is the provision of mechanism of thischaracter, wherein the use of toothed gear transmission is entirelydispensed with, and the speed change between the driving and drivenmediums is automatically effected corresponding to load conditionspresent in a motor vehicle, the mechanism being of novel constructionand is unique in the assembly of the parts thereof.

A still further object of the invention is the provision of mechanism ofthis character, which is simple in construction, thoroughly reliable andeihcient in operation, strong, durable, positive in the working thereof,compact, readily and easily assembled, and inexpensive to manufactureand install.

With these and other objects in view the invention consists in thefeatures of construction, combination and arrangement of parts as willbe hereinafter more fully described, illustrated in the accompanyingdrawings, which disclose the preferred embodiment of the invention, andpointed out in the claims hereunto appended.

In the accompanying drawings:

Figure 1 is a fragmentary plan view of the mechanism constructed inaccordance with the invention.

Figure 2 is a sectional view taken approximately on the line 22 ofFigure 1, looking in the direction of the arrows.

Figure 3 is a view similar to Figure 2 taken at right angles thereto.

Figure 4 is a sectional view taken on the line l4 of Figure 1, lookingin the direction of the arrows.

2 Claims. (01. 74-'196 h in] Similar reference characters indicate correspondingparts throughout the several viewsin the drawings. l v

Referrin to the drawings in detail, the mechanism constituting thepresent invention relates to a variable speed friction geartransmission, come prising a. power unit shaft, only a portion thereofdesignate-d'generaily at A, and a drivenshaft, a portion of thelatterbeing denoted at B, and these shafts are mounted in the respectivestationary bearings li, and H, which are supportedfina chassis frame, aportion of which denoted at P2, of a motor vehicle, not shown.

Loose for free rotation on the driven shaft B are spaced disk-likefriction gears l3 and I4, respectively, while splined at l5 betweenthese gears is a clutch sleeve l6 adapted for sliding movement on theshaft B to engage with and disengage from either of the gears l3 and I4,alternately, and in this manner a reversal of the direction of rotationof the driven shaft will be had, as hereinafter described.

Parallel with and at opposite sides of the lay of the driving and drivenshafts A and B, as well as spaced therefrom, are inside and outsidetracks I! and I8, respectively, which are made secure by fasteners l9,and fitted to these tracks are runners 29 provided with bearings 2i forstud arbors 22, which are disposed at right angles to the shafts atopposite sides thereof and laterally confront the same. Loose on thesearbors 22 are change speed friction disks 23, which are backed by thrustbearings 24, and against the latter work coiled tensioning springs 25trained about the arbors 22 with contact against the outer runnerbearings 2| to hold such disks '23 in contact at all times with theperipheries of the gears l3 and [4, whether clutched to or unclutchedfrom the shaft B.

The driving shaft A has fixed thereto a friction disk drivin gear 26,which meshes with the disks 23 at all times. Connected by pivots 21 torunners 2!] are the arms 28 of a shift yoke 29, these arms being pivotedat 3D to a throw elbow 3! having a worm threaded sector 32, meshing witha worm feed screw 33 formed on a turning shaft 3'!- fitting suitablebearings 35 statio-narily supported.

The shaft 34 has a crank arm 36 attached thereto, and to the latter ispivoted at 3'! to the oifset portion 38 of a piston stem or rod 39, itspiston 40 operating in the cylinder 4! of a vacuum operated motor orother like device, which is suitably supported in the chassis frame l2,the suction pipe line 42 of which has connection with the suctionmanifold, not shown, of the vehicle motor. The line 42 is fitted with ableed valve device 43 operative by the motor vehicle clutch pedal 44, asbest seen in Figure 1 of the drawings. When the pedal 44 is depressed,the valve 43 is opened to thereby actuate the piston 40. The motor orother like device having the piston 40 and the cylinder 4| automaticallycontrols the throw of the disks 23, to bring the same toward and fromthe center of the gears 13, I4 and 26 accordingly to the load imposed onthe motor by the vehicle, and in this way regulating the speed changesof motions between the motor drive shaft A and the driven shaft B.

The clutch sleeve I6 is manually thrown by a hand throw lever 45, forreverse driving action of the transmission mechanism.

The piston 40 for its return stroke within the cylinder when suction orvacuum action thereon is relieved, has acting thereon a tensioningspring 46 connected to the shaft 34, as best seen in Figure 1 of thedrawings.

When the motor is subjected to a light load the vacuum is the greatestin accordance therewith, so that the gears 13 and 26 approach the centerof the disks 23, and gear I4 approaches the outer edge of disks 23. Whenthe load increases the gears recede from their positions of the saiddisks, and in this manner the driven speed automatically varies betweenthe driving and driven shafts congruous with the load imposed by thevehicle in the driving thereof, either forwardly or back- 4 wardly. Thevacuum effect is manually controlled by an operator of the vehiclethrough the use of the motor vehicle clutch pedal 44, as beforedescribed.

What is claimed is:

1. Mechanism of the character described, comprising a rotary drivingelement, a rotary driven element, opposed friction disks parallel withand confronting the driving and driven elements, friction gears loose onthe driven element and engaging the disks, at opposite sides of thecenters thereof, means for clutching either gear to the driven element,and friction gear connections between the driving element and the saiddisks.

2. The invention as in claim 1 including means for varying the ratio ofspeed between the driving element and the driven element comprisingmeans for varying the position of the disks along a direction parallelto the axis of the driving element.

WAYNE LEHNERT.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 478,959 Gordon July 12, 1892967,279 Whitcomb Aug. 16, 1910 2,115,097 Durham Apr. 26, 1938 2,116,590Tyler May 10, 1938

